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1.
Food Res Int ; 188: 114496, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823843

RESUMO

Agro-industrial co-products, such as fish gelatin, stand out for their capacity in forming biopolymeric films, being biocompatible and non-toxic; however, its hydrophilicity poses a challenge. Essential oils, rich in bioactives, attract research interest aiming to enhance the protective barrier of films and enable their application in packaging. This study produced films based on cross-linked Nile tilapia skin gelatin, incorporating garlic essential oil. Gelatin obtained through partial collagen hydrolysis from the fish skin and cross-linked with gallic acid had hydroxyproline content of 10.02 g 100 g-1 and gel strength of 287 g, which were consistent with other studies. Oil extraction used supercritical CO2 as a solvent and ethanol as a cosolvent, following a factorial experimental design, evaluating the extraction temperature (40 °C and 70 °C) and cosolvent ratio (1:1 and 1:3), with three central points. Extraction was successful, with higher yields on a dry basis at 70 °C (88.35 %), using a 1:1 cosolvent ratio. Films incorporated with oil exhibited lower water vapor permeability (WVP) than those with only cross-linked gelatin (1.59 (g m-1 s-1 Pa-1) 1011). The film with the most suitable tensile strength (19.07 MPa), elongation (120.91 %), and WVP (1.09 (g m-1 s-1 Pa-1) 1011) properties contained garlic oil extracted at the central point (55 °C and 1:2). Thermal analysis indicated increased melting temperatures in films with added oil, suggesting low thermal degradation. These results suggest that garlic oil addition can improve the properties of fish gelatin-based films, making them promising for biodegradable packaging.


Assuntos
Embalagem de Alimentos , Alho , Gelatina , Óleos Voláteis , Permeabilidade , Gelatina/química , Óleos Voláteis/química , Animais , Alho/química , Embalagem de Alimentos/métodos , Resistência à Tração , Vapor , Sulfetos/química , Interações Hidrofóbicas e Hidrofílicas , Pele/química
2.
PLoS One ; 19(5): e0301142, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38718088

RESUMO

Steel cord materials were found to have internal porous microstructures and complex fluid flow properties. However, current studies have rarely reported the transport behavior of steel cord materials from a microscopic viewpoint. The computed tomography (CT) scanning technology and lattice Boltzmann method (LBM) were used in this study to reconstruct and compare the real three-dimensional (3D) pore structures and fluid flow in the original and tensile (by loading 800 N force) steel cord samples. The pore-scale LBM results showed that fluid velocities increased as displacement differential pressure increased in both the original and tensile steel cord samples, but with two different critical values of 3.3273 Pa and 2.6122 Pa, respectively. The original steel cord sample had higher maximal and average seepage velocities at the 1/2 sections of 3D construction images than the tensile steel cord sample. These phenomena should be attributed to the fact that when the original steel cord sample was stretched, its porosity decreased, pore radius increased, flow channel connectivity improved, and thus flow velocity increased. Moreover, when the internal porosity of tensile steel cord sample was increased by 1 time, lead the maximum velocity to increase by 1.52 times, and the average velocity was increased by 1.66 times. Furthermore, when the density range was determined to be 0-38, the pore phase showed the best consistency with the segmentation area. Depending on the Zou-He Boundary and Regularized Boundary, the relative error of simulated average velocities was only 0.2602 percent.


Assuntos
Aço , Aço/química , Porosidade , Resistência à Tração , Hidrodinâmica , Tomografia Computadorizada por Raios X
3.
Clin Oral Investig ; 28(6): 305, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722356

RESUMO

OBJECTIVE: To evaluate the ability of the water glass treatment to penetrate zirconia and improve the bond strength of resin cement. MATERIAL AND METHODS: Water glass was applied to zirconia specimens, which were then sintered. The specimens were divided into water-glass-treated and untreated zirconia (control) groups. The surface properties of the water-glass-treated specimens were evaluated using surface roughness and electron probe micro-analyser (EPMA) analysis. A resin cement was used to evaluate the tensile bond strength, with2 and without a silane-containing primer. After 24 h in water storage at 37 °C and thermal cycling, the bond strengths were statistically evaluated with t-test, and the fracture surfaces were observed using SEM. RESULTS: The water glass treatment slightly increased the surface roughness of the zirconia specimens, and the EPMA analysis detected the water glass penetration to be 50 µm below the zirconia surface. The application of primer improved the tensile bond strength in all groups. After 24 h, the water-glass-treated zirconia exhibited a tensile strength of 24.8 ± 5.5 MPa, which was significantly higher than that of the control zirconia (17.6 ± 3.5 MPa) (p < 0.05). After thermal cycling, the water-glass-treated zirconia showed significantly higher tensile strength than the control zirconia. The fracture surface morphology was mainly an adhesive pattern, whereas resin cement residue was occasionally detected on the water-glass-treated zirconia surfaces. CONCLUSION: The water glass treatment resulted in the formation of a stable silica phase on the zirconia surface. This process enabled silane coupling to the zirconia and improved the adhesion of the resin cement.


Assuntos
Colagem Dentária , Vidro , Teste de Materiais , Cimentos de Resina , Silanos , Propriedades de Superfície , Resistência à Tração , Água , Zircônio , Zircônio/química , Cimentos de Resina/química , Silanos/química , Água/química , Colagem Dentária/métodos , Vidro/química , Microscopia Eletrônica de Varredura , Análise do Estresse Dentário
4.
Carbohydr Polym ; 337: 122112, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38710545

RESUMO

The growing concerns on environmental pollution and sustainability have raised the interest on the development of functional biobased materials for different applications, including food packaging, as an alternative to the fossil resources-based counterparts, currently available in the market. In this work, functional wood inspired biopolymeric nanocomposite films were prepared by solvent casting of suspensions containing commercial beechwood xylans, cellulose nanofibers (CNF) and lignosulfonates (magnesium or sodium), in a proportion of 2:5:3 wt%, respectively. All films presented good homogeneity, translucency, and thermal stability up to 153 °C. The incorporation of CNF into the xylan/lignosulfonates matrix provided good mechanical properties to the films (Young's modulus between 1.08 and 3.79 GPa and tensile strength between 12.75 and 14.02 MPa). The presence of lignosulfonates imparted the films with antioxidant capacity (DPPH radical scavenging activity from 71.6 to 82.4 %) and UV barrier properties (transmittance ≤19.1 % (200-400 nm)). Moreover, the films obtained are able to successfully delay the browning of packaged fruit stored over 7 days at 4 °C. Overall, the obtained results show the potential of using low-cost and eco-friendly resources for the development of sustainable active food packaging materials.


Assuntos
Celulose , Embalagem de Alimentos , Lignina , Lignina/análogos & derivados , Nanocompostos , Nanofibras , Resistência à Tração , Madeira , Xilanos , Embalagem de Alimentos/métodos , Lignina/química , Nanocompostos/química , Celulose/química , Celulose/análogos & derivados , Madeira/química , Nanofibras/química , Xilanos/química , Antioxidantes/química , Frutas/química
5.
Molecules ; 29(9)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38731542

RESUMO

Bilayer electrospun fibers aimed to be used for skin tissue engineering applications were fabricated for enhanced cell attachment and proliferation. Different ratios of PHBV-PLLA (70:30, 80:20, and 90:10 w/w) blends were electrospun on previously formed electrospun PHBV membranes to produce their bilayers. The fabricated electrospun membranes were characterized with FTIR, which conformed to the characteristic peaks assigned for both PHBV and PLLA. The surface morphology was evaluated using SEM analysis that showed random fibers with porous morphology. The fiber diameter and pore size were measured in the range of 0.7 ± 0.1 µm and 1.9 ± 0.2 µm, respectively. The tensile properties of the bilayers were determined using an electrodynamic testing system. Bilayers had higher elongation at break (44.45%) compared to the monolayers (28.41%) and improved ultimate tensile strength (7.940 MPa) compared to the PHBV monolayer (2.450 MPa). In vitro cytotoxicity of each of the scaffolds was determined via culturing MC3T3 (pre-osteoblastic cell line) on the membranes. Proliferation was evaluated using the Alamar Blue assay on days 3, 7, and 14, respectively. SEM images of cells cultured on membranes were taken in addition to bright field imaging to visually show cell attachment. Fluorescent nuclear staining performed with DAPI was imaged with an inverted fluorescent microscope. The fabricated bilayer shows high mechanical strength as well as biocompatibility with good cell proliferation and cell attachment, showing potential for skin substitute applications.


Assuntos
Materiais Biocompatíveis , Proliferação de Células , Poliésteres , Pele , Engenharia Tecidual , Alicerces Teciduais , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Poliésteres/química , Animais , Camundongos , Proliferação de Células/efeitos dos fármacos , Alicerces Teciduais/química , Resistência à Tração , Membranas Artificiais , Linhagem Celular , Teste de Materiais , Polímeros/química , Adesão Celular/efeitos dos fármacos
6.
Sci Rep ; 14(1): 10825, 2024 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734808

RESUMO

This study developed a kind of PEG-crosslinked O-carboxymethyl chitosan (O-CMC-PEG) with various PEG content for food packaging. The crosslinking agent of isocyanate-terminated PEG was firstly synthesized by a simple condensation reaction between PEG and excess diisocyanate, then the crosslink between O-carboxymethyl chitosan (O-CMC) and crosslinking agent occurred under mild conditions to produce O-CMC-PEG with a crosslinked structure linked by urea bonds. FT-IR and 1H NMR techniques were utilized to confirm the chemical structures of the crosslinking agent and O-CMC-PEGs. Extensive research was conducted to investigate the impact of the PEG content (or crosslinking degree) on the physicochemical characteristics of the casted O-CMC-PEG films. The results illuminated that crosslinking and components compatibility could improve their tensile features and water vapor barrier performance, while high PEG content played the inverse effects due to the microphase separation between PEG and O-CMC segments. The in vitro degradation rate and water sensitivity primarily depended on the crosslinking degree in comparison with the PEG content. Furthermore, caused by the remaining -NH2 groups of O-CMC, the films demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. When the PEG content was 6% (medium crosslinking degree), the prepared O-CMC-PEG-6% film possessed optimal tensile features, high water resistance, appropriate degradation rate, low water vapor transmission rate and fine broad-spectrum antibacterial capacity, manifesting a great potential for application in food packaging to extend the shelf life.


Assuntos
Antibacterianos , Quitosana , Escherichia coli , Embalagem de Alimentos , Polietilenoglicóis , Quitosana/química , Quitosana/análogos & derivados , Quitosana/farmacologia , Embalagem de Alimentos/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Polietilenoglicóis/química , Escherichia coli/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Resistência à Tração
7.
AAPS PharmSciTech ; 25(5): 116, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769223

RESUMO

Oral dispersible films have received broad interest due to fast drug absorption and no first-path metabolism, leading to high bioavailability and better patient compliance. Saxagliptin (SXG) is an antidiabetic drug that undergoes first-path metabolism, resulting in a less active metabolite, so the development of SXG oral dispersible films (SXG-ODFs) improves SXG bioavailability. The formula optimisation included a response surface experimental design and the impact of three formulation factors, the type and concentration of polymer and plasticiser concentration on in-vitro disintegration time and folding endurance. Two optimised SXG-ODFs prepared using either polyvinyl alcohol (PVA) or hydroxypropyl methylcellulose were investigated. SXG-ODFs prepared with PVA demonstrated a superior rapid disintegration time, ranging from 17 to 890 s, with the fastest disintegration time recorded at 17 s. These short durations can be attributed to the hydrophilic nature of PVA, facilitating rapid hydration and disintegration upon contact with saliva. Additionally, PVA-based films displayed remarkable folding endurance, surpassing 200 folds without rupture, indicating flexibility and stability. The high tensile strength of PVA-based films further underscores their robust mechanical properties, with tensile strength values reaching up to 4.53 MPa. SXG exhibits a UV absorption wavelength of around 212 nm, posing challenges for traditional quantitative spectrophotometric analysis, so a polyaniline nanoparticles-based solid-contact screen-printed ion-selective electrode (SP-ISE) was employed for the determination of SXG release profile effectively in comparison to HPLC. SP-ISE showed a better real-time release profile of SXG-ODFs, and the optimised formula showed lower blood glucose levels than commercial tablets.


Assuntos
Adamantano , Compostos de Anilina , Dipeptídeos , Liberação Controlada de Fármacos , Nanopartículas , Álcool de Polivinil , Adamantano/química , Adamantano/análogos & derivados , Dipeptídeos/química , Dipeptídeos/farmacocinética , Dipeptídeos/administração & dosagem , Compostos de Anilina/química , Nanopartículas/química , Administração Oral , Álcool de Polivinil/química , Hipoglicemiantes/química , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacocinética , Humanos , Derivados da Hipromelose/química , Resistência à Tração , Química Farmacêutica/métodos , Disponibilidade Biológica , Solubilidade , Eletrodos
8.
J Adhes Dent ; 26(1): 135-145, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38771025

RESUMO

PURPOSE: To measure zirconia-to-zirconia microtensile bond strength (µTBS) using composite cements with and without primer. MATERIALS AND METHODS: Two Initial Zirconia UHT (GC) sticks (1.8x1.8x5.0 mm) were bonded using four cements with and without their respective manufacturer's primer/adhesive (G-CEM ONE [GOne] and G-Multi Primer, GC; Panavia V5 [Pv5]), and Panavia SA Cement Universal [PSAu], and Clearfil Ceramic Plus, Kuraray Noritake; RelyX Universal (RXu) and Scotchbond Universal Plus [SBUp], 3M Oral Care). Specimens were trimmed to an hour-glass shaped specimen whose isthmus is circular in cross-section. After 1-week water storage, the specimens were either tested immediately (1-week µTBS) or first subjected to 50,000 thermocycles (50kTC-aged µTBS). The fracture mode was categorized as either adhesive interfacial failure, cohesive failure in composite cement, or mixed failure, followed by SEM fracture analysis of selected specimens. Data were analyzed using linear mixed-effects statistics (α = 0.05; variables: composite cement, primer/adhesive application, aging). RESULTS: The statistical analysis revealed no significant differences with aging (p = 0.3662). No significant difference in µTBS with/without primer and aging was recorded for GOne and PSAu. A significantly higher µTBS was recorded for Pv5 and RXu when applied with their respective primer/adhesive. Comparing the four composite cements when they were applied in the manner that resulted in their best performance, a significant difference in 50kTC-aged µTBS was found for PSAu compared to Pv5 and RXu. A significant decrease in µTBS upon 50kTC aging was only recorded for RXu in combination with SBUp. CONCLUSION: Adequate bonding to zirconia requires the functional monomer 10-MDP either contained in the composite cement, in which case a separate 10-MDP primer is no longer needed, or in the separately applied primer/adhesive.


Assuntos
Resinas Compostas , Colagem Dentária , Teste de Materiais , Metacrilatos , Cimentos de Resina , Resistência à Tração , Zircônio , Zircônio/química , Cimentos de Resina/química , Resinas Compostas/química , Metacrilatos/química , Cimentos Dentários/química , Cerâmica/química , Análise do Estresse Dentário , Humanos , Fatores de Tempo , Água/química , Temperatura , Porcelana Dentária/química , Propriedades de Superfície , Materiais Dentários/química , Cimentos de Ionômeros de Vidro
9.
Biomed Mater ; 19(4)2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38729187

RESUMO

Bundles of engineered collagen microfibers are promising synthetic tendons as substitutes for autogenous grafts. The purpose of this study was to develop high-speed and continuous spinning of collagen microfibers that involves stretching of collagen stream. Our study revealed the 'critical fibrillogenesis concentration (CFC)' of neutralized collagen solutions, which is defined as the upper limit of the collagen concentration at which neutralized collagen molecules remain stable as long as they are cooled (⩽10 °C). Neutralized collagen solutions at collagen concentrations slightly below the CFC formed cord-like collagen gels comprising longitudinally aligned fibrils when extruded from nozzles into an ethanol bath. Dry collagen microfibers with a controlled diameter ranging from 122 ± 2-31.2 ± 1.7 µm can be spun from the cord-like gels using nozzles of various sizes. The spinning process was improved by including stretching of collagen stream to further reduce diameter and increase linear velocity. We extruded a collagen solution through a 182 µm diameter nozzle while simultaneously stretching it in an ethanol bath during gelation and fiber formation. This process resembles the stretching of a melted thermoplastic resin because it solidifies during melt spinning. The mechanical properties of the stretched collagen microfibers were comparable to the highest literature values obtained using microfluidic wet spinning, as they exhibited longitudinally aligned fibrils both on their surface and in their core. Previous wet spinning methods were unable to generate collagen microfibers with a consistent tendon-like fibrillar arrangement throughout the samples. Although the tangent modulus (137 ± 7 MPa) and stress at break of the swollen bundles of stretched microfibers (13.8 ± 1.9 MPa) were lower than those of human anterior cruciate ligament, they were within the same order of magnitude. We developed a spinning technique that produces narrow collagen microfibers with a tendon-like arrangement that can serve as artificial fiber units for collagen-based synthetic tendons.


Assuntos
Colágeno , Teste de Materiais , Tendões , Engenharia Tecidual , Colágeno/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/química , Humanos , Resistência à Tração , Estresse Mecânico , Alicerces Teciduais/química
10.
PLoS One ; 19(5): e0301216, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38743641

RESUMO

Non-thermal atmospheric-pressure plasma (NTAPP) has been widely studied for clinical applications, e.g., disinfection, wound healing, cancer therapy, hemostasis, and bone regeneration. It is being revealed that the physical and chemical actions of plasma have enabled these clinical applications. Based on our previous report regarding plasma-stimulated bone regeneration, this study focused on Achilles tendon repair by NTAPP. This is the first study to reveal that exposure to NTAPP can accelerate Achilles tendon repair using a well-established Achilles tendon injury rat model. Histological evaluation using the Stoll's and histological scores showed a significant improvement at 2 and 4 weeks, with type I collagen content being substantial at the early time point of 2 weeks post-surgery. Notably, the replacement of type III collagen with type I collagen occurred more frequently in the plasma-treated groups at the early stage of repair. Tensile strength test results showed that the maximum breaking strength in the plasma-treated group at two weeks was significantly higher than that in the untreated group. Overall, our results indicate that a single event of NTAPP treatment during the surgery can contribute to an early recovery of an injured tendon.


Assuntos
Tendão do Calcâneo , Gases em Plasma , Traumatismos dos Tendões , Cicatrização , Animais , Tendão do Calcâneo/lesões , Ratos , Gases em Plasma/farmacologia , Gases em Plasma/uso terapêutico , Cicatrização/efeitos dos fármacos , Traumatismos dos Tendões/terapia , Masculino , Hélio/farmacologia , Ratos Sprague-Dawley , Colágeno Tipo I/metabolismo , Resistência à Tração , Pressão Atmosférica , Colágeno Tipo III/metabolismo
11.
Am J Dent ; 37(2): 71-77, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38704849

RESUMO

PURPOSE: To investigate the effect of painless low-power Er:YAG laser irradiation of conventional and polymer-infiltrated ceramic network (PICN) type CAD-CAM resin-based composites (RBCs) on resin bonding. METHODS: An Er:YAG laser system, phosphoric acid etchant, universal adhesive, RBC, and two types of CAD-CAM RBC block were used. Microtensile bond strength, fracture mode, scanning electron microscopy (SEM) observations of bonding interfaces and CAD-CAM surfaces, and surface roughness of ground and pretreated surfaces were investigated. As pretreatment methods, low-power Er:YAG laser irradiation and air-abrasion with alumina particles were used. RESULTS: The effect of low-power Er:YAG laser irradiation of CAD-CAM RBCs on bonding to repair resin varied depending on the type of CAD-CAM RBCs. CLINICAL SIGNIFICANCE: The low-power Er:YAG laser irradiation of the conventional CAD-CAM RBCs was shown to be effective as a surface pretreatment for resin bonding, while the laser irradiation of PICN-type CAD-CAM RBCs was not effective.


Assuntos
Resinas Compostas , Desenho Assistido por Computador , Colagem Dentária , Lasers de Estado Sólido , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resinas Compostas/química , Resistência à Tração , Teste de Materiais , Humanos , Cerâmica/química , Condicionamento Ácido do Dente
12.
Med Eng Phys ; 127: 104158, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692761

RESUMO

BACKGROUND: The intervertebral disc exhibits not only strain rate dependence (viscoelasticity), but also significant asymmetry under tensile and compressive loads, which is of great significance for understanding the mechanism of lumbar disc injury under physiological loads. OBJECTIVE: In this study, the strain rate sensitive and tension-compression asymmetry of the intervertebral disc were analyzed by experiments and constitutive equation. METHOD: The Sheep intervertebral disc samples were divided into three groups, in order to test the strain rate sensitive mechanical behavior, and the internal displacement as well as pressure distribution. RESULTS: The tensile stiffness is one order of magnitude smaller than the compression stiffness, and the logarithm of the elastic modulus is approximately linear with the logarithm of the strain rate, showing obvious tension-compression asymmetry and rate-related characteristics. In addition, the sensitivity to the strain rate is the same under these two loading conditions. The stress-strain curves of unloading and loading usually do not coincide, and form a Mullins effect hysteresis loop. The radial displacement distribution is opposite between the anterior and posterior region, which is consistent with the stress distribution. By introducing the damage factor into ZWT constitutive equation, the rate-dependent viscoelastic and weakening behavior of the intervertebral disc can be well described.


Assuntos
Força Compressiva , Disco Intervertebral , Estresse Mecânico , Animais , Disco Intervertebral/fisiologia , Ovinos , Fenômenos Biomecânicos , Resistência à Tração , Suporte de Carga , Elasticidade
13.
AAPS PharmSciTech ; 25(5): 101, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714629

RESUMO

BACKGROUND: Niacin, an established therapeutic for dyslipidemia, is hindered by its propensity to induce significant cutaneous flushing when administered orally in its unmodified state, thereby constraining its clinical utility. OBJECTIVE: This study aimed to fabricate, characterize, and assess the in-vitro and in-vivo effectiveness of niacin-loaded polymeric films (NLPFs) comprised of carboxymethyl tamarind seed polysaccharide. The primary objective was to mitigate the flushing-related side effects associated with oral niacin administration. METHODS: NLPFs were synthesized using the solvent casting method and subsequently subjected to characterization, including assessments of tensile strength, moisture uptake, thickness, and folding endurance. Surface characteristics were analyzed using a surface profiler and scanning electron microscopy (SEM). Potential interactions between niacin and the polysaccharide core were investigated through X-ray diffraction experiments (XRD) and Fourier transform infrared spectroscopy (FTIR). The viscoelastic properties of the films were explored using a Rheometer. In-vitro assessments included drug release studies, swelling behavior assays, and antioxidant assays. In-vivo efficacy was evaluated through skin permeation assays, skin irritation assays, and histopathological analyses. RESULTS: NLPFs exhibited a smooth texture with favorable tensile strength and moisture absorption capabilities. Niacin demonstrated interaction with the polysaccharide core, rendering the films amorphous. The films displayed slow and sustained drug release, exceptional antioxidant properties, optimal swelling behavior, and viscoelastic characteristics. Furthermore, the films exhibited biocompatibility and non-toxicity towards skin cells. CONCLUSION: NLPFs emerged as promising carrier systems for the therapeutic transdermal delivery of niacin, effectively mitigating its flushing-associated adverse effects.


Assuntos
Administração Cutânea , Liberação Controlada de Fármacos , Niacina , Polissacarídeos , Ratos Wistar , Absorção Cutânea , Pele , Animais , Ratos , Niacina/administração & dosagem , Niacina/química , Niacina/farmacologia , Polissacarídeos/química , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Pele/metabolismo , Pele/efeitos dos fármacos , Absorção Cutânea/efeitos dos fármacos , Rubor/induzido quimicamente , Resistência à Tração , Masculino , Sistemas de Liberação de Medicamentos/métodos , Tamarindus/química , Polímeros/química
14.
Eur J Med Res ; 29(1): 264, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38698476

RESUMO

BACKGROUND: The fundamental prerequisite for prognostically favorable postoperative results of peripheral nerve repair is stable neurorrhaphy without interruption and gap formation. METHODS: This study evaluates 60 neurorrhaphies on femoral chicken nerves in terms of the procedure and the biomechanical properties. Sutured neurorrhaphies (n = 15) served as control and three sutureless adhesive-based nerve repair techniques: Fibrin glue (n = 15), Histoacryl glue (n = 15), and the novel polyurethane adhesive VIVO (n = 15). Tensile and elongation tests of neurorrhaphies were performed on a tensile testing machine at a displacement rate of 20 mm/min until failure. The maximum tensile force and elongation were recorded. RESULTS: All adhesive-based neurorrhaphies were significant faster in preparation compared to sutured anastomoses (p < 0.001). Neurorrhaphies by sutured (102.8 [cN]; p < 0.001), Histoacryl (91.5 [cN]; p < 0.001) and VIVO (45.47 [cN]; p < 0.05) withstood significant higher longitudinal tensile forces compared to fibrin glue (10.55 [cN]). VIVO, with △L/L0 of 6.96 [%], showed significantly higher elongation (p < 0.001) compared to neurorrhaphy using fibrin glue. CONCLUSION: Within the limitations of an in vitro study the adhesive-based neurorrhaphy technique with VIVO and Histoacryl have the biomechanical potential to offer alternatives to sutured neuroanastomosis because of their stability, and faster handling. Further in vivo studies are required to evaluate functional outcomes and confirm safety.


Assuntos
Anastomose Cirúrgica , Galinhas , Resistência à Tração , Animais , Anastomose Cirúrgica/métodos , Fenômenos Biomecânicos , Adesivos Teciduais/farmacologia , Adesivo Tecidual de Fibrina/farmacologia , Nervos Periféricos/cirurgia , Nervos Periféricos/fisiologia , Adesivos , Procedimentos Neurocirúrgicos/métodos
15.
J Mech Behav Biomed Mater ; 155: 106564, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38749267

RESUMO

Polycaprolactone (PCL) nanofibers are a promising material for biomedical applications due to their biocompatibility, slow degradation rate, and thermal stability. We electrospun PCL fibers onto a striated substrate with 12 µm wide ridges and grooves and determined their mechanical properties in an aqueous solution with a combined atomic force/inverted optical microscopy technique. Fiber diameters, D, ranged from 27 to 280 nm. The hydrated PCL fibers had an extensibility (breaking strain), εmax, of 137%. The Young's modulus, E, and tensile strength, σT, showed a strong dependence on fiber diameter, D; decreasing steeply with increasing diameter, following empirical equations E(D)=(4.3∙103∙e-D51nm+1.1∙102) MPa and σT(D)=(2.6∙103∙e-D55nm+0.6∙102) MPa. Incremental stress-strain measurements were employed to investigate the viscoelastic behavior of these fibers. The fibers exhibited stress relaxation with a fast and slow relaxation time of 3.7 ± 1.2 s and 23 ± 8 s and these experiments also allowed the determination of the elastic and viscous moduli. Cyclic stress-strain curves were used to determine that the elastic limit of the fibers, εelastic, is between 19% and 36%. These curves were also used to determine that these fibers showed small energy losses (<20%) at small strains (ε < 10%), and over 50% energy loss at large strains (ε > 50%), asymptotically approaching 61%, as Eloss=61%·(1-e-0.04*ε). Our work is the first mechanical characterization of hydrated electrospun PCL nanofibers; all previous experiments were performed on dry PCL fibers, to which we will compare our data.


Assuntos
Teste de Materiais , Nanofibras , Poliésteres , Estresse Mecânico , Água , Poliésteres/química , Nanofibras/química , Água/química , Fenômenos Mecânicos , Resistência à Tração , Módulo de Elasticidade , Viscosidade , Materiais Biocompatíveis/química
16.
Int J Mol Sci ; 25(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38791364

RESUMO

The use of natural active substances and the development of new formulations are promising directions in the cosmetic and pharmacy industries. The primary purpose of this research was the production of microparticles based on whey protein isolate (WPI) and calcium alginate (ALG) containing Calendula officinalis flower extract and their incorporation into films composed of gelatin, WPI, and glycerol. Both swollen and dry microparticles were studied by optical microscopy and their sizes were measured. Water absorption by the microparticles, their loading capacity, and the release profile of flower extract were also characterized. The films were analyzed by mechanical tests (Young's modulus, tensile strength, elongation at break), swelling capacity, contact angle, and moisture content measurements. The presented data showed that the active ingredient was successfully enclosed in spherical microparticles and completely released after 75 min of incubation at 37 °C. The incorporation of the microparticles into polymer films caused a decrease in stiffness and tensile strength, simultaneously increasing the ductility of the samples. Moreover, the films containing microparticles displayed higher swelling ability and moisture content compared to those without them. Hence, the materials prepared in this study with Calendula officinalis flower extract encapsulated into polymeric microspheres can be a starting point for the development of new products intended for skin application; advantages include protection of the extract against external factors and a controlled release profile.


Assuntos
Calendula , Preparações de Ação Retardada , Flores , Extratos Vegetais , Resistência à Tração , Proteínas do Soro do Leite , Calendula/química , Flores/química , Extratos Vegetais/química , Proteínas do Soro do Leite/química , Preparações de Ação Retardada/química , Alginatos/química , Gelatina/química , Microesferas
17.
Molecules ; 29(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38792175

RESUMO

Anthocyanin-rich steamed purple sweet potato (SPSP) is a suitable raw material to produce smart packaging films. However, the application of SPSP-based films is restricted by the low antimicrobial activity of anthocyanins. In this study, SPSP-based smart packaging films were produced by adding mandarin essential oil (MEO) as an antimicrobial agent. The impact of MEO content (3%, 6%, and 9%) on the structures, properties, and application of SPSP-based films was measured. The results showed that MEO created several pores within films and reduced the hydrogen bonding system and crystallinity of films. The dark purple color of the SPSP films was almost unchanged by MEO. MEO significantly decreased the light transmittance, water vapor permeability, and tensile strength of the films, but remarkably increased the oxygen permeability, thermal stability, and antioxidant and antimicrobial properties of the films. The SPSP-MEO films showed intuitive color changes at different acid-base conditions. The purple-colored SPSP-MEO films turned blue when chilled shrimp and pork were not fresh. The MEO content greatly influenced the structures, physical properties, and antioxidant and antimicrobial activities of the films. However, the MEO content had no impact on the color change ability of the films. The results suggested that SPSP-MEO films have potential in the smart packaging of protein-rich foods.


Assuntos
Embalagem de Alimentos , Ipomoea batatas , Óleos Voláteis , Permeabilidade , Ipomoea batatas/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Embalagem de Alimentos/métodos , Antioxidantes/química , Antioxidantes/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Vapor , Resistência à Tração , Antocianinas/química , Antocianinas/farmacologia , Cor
18.
Am J Bot ; 111(5): e16349, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38783552

RESUMO

PREMISE: Leaf tensile resistance, a leaf's ability to withstand pulling forces, is an important determinant of plant ecological strategies. One potential driver of leaf tensile resistance is growing season length. When growing seasons are long, strong leaves, which often require more time and resources to construct than weak leaves, may be more advantageous than when growing seasons are short. Growing season length and other ecological conditions may also impact the morphological traits that underlie leaf tensile resistance. METHODS: To understand variation in leaf tensile resistance, we measured size-dependent leaf strength and size-independent leaf toughness in diverse genotypes of the widespread perennial grass Panicum virgatum (switchgrass) in a common garden. We then used quantitative genetic approaches to estimate the heritability of leaf tensile resistance and whether there were genetic correlations between leaf tensile resistance and other morphological traits. RESULTS: Leaf tensile resistance was positively associated with aboveground biomass (a proxy for fitness). Moreover, both measures of leaf tensile resistance exhibited high heritability and were positively genetically correlated with leaf lamina thickness and leaf mass per area (LMA). Leaf tensile resistance also increased with the growing season length in the habitat of origin, and this effect was mediated by both LMA and leaf thickness. CONCLUSIONS: Differences in growing season length may promote selection for different leaf lifespans and may explain existing variation in leaf tensile resistance in P. virgatum. In addition, the high heritability of leaf tensile resistance suggests that P. virgatum will be able to respond to climate change as growing seasons lengthen.


Assuntos
Folhas de Planta , Estações do Ano , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Panicum/genética , Panicum/fisiologia , Panicum/anatomia & histologia , Panicum/crescimento & desenvolvimento , Resistência à Tração , Biomassa , Fenótipo , Genótipo , Característica Quantitativa Herdável
19.
Int J Pharm ; 657: 124190, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38701910

RESUMO

Lubricants are essential for most tablet formulations as they assist powder flow, prevent adhesion to tableting tools and facilitate tablet ejection. Magnesium stearate (MgSt) is an effective lubricant but may compromise tablet strength and disintegratability. In the design of orodispersible tablets, tablet strength and disintegratability are critical attributes of the dosage form. Hence, this study aimed to conduct an in-depth comparative study of MgSt with alternative lubricants, namely sodium lauryl sulphate (SLS), stearic acid (SA) and hydrogenated castor oil (HCO), for their effects on the tableting process as well as tablet properties. Powder blends were prepared with lactose, sodium starch glycolate or crospovidone as the disintegrant, and a lubricant at different concentrations. Angle of repose was determined for the mixtures. Comparative evaluation was carried out based on the ejection force, tensile strength, liquid penetration and disintegratability of the tablets produced. As the lubricant concentration increased, powder flow and tablet ejection improved. The lubrication efficiency generally decreased as follows: MgSt > HCO > SA > SLS. Despite its superior lubrication efficacy, MgSt is the only lubricant of four evaluated that reduced tablet tensile strength. Tablet disintegration time was strongly determined by tensile strength and liquid penetration, which were in turn affected by the lubricant type and concentration. All the above factors should be taken into consideration when deciding the type and concentration of lubricant for an orodispersible tablet formulation.


Assuntos
Excipientes , Lubrificantes , Ácidos Esteáricos , Comprimidos , Resistência à Tração , Lubrificantes/química , Ácidos Esteáricos/química , Excipientes/química , Composição de Medicamentos/métodos , Pós/química , Dodecilsulfato de Sódio/química , Óleo de Rícino/química , Povidona/química , Amido/química , Amido/análogos & derivados , Lactose/química , Administração Oral , Solubilidade , Química Farmacêutica/métodos
20.
Biosensors (Basel) ; 14(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38785701

RESUMO

At the heart of the non-implantable electronic revolution lies ionogels, which are remarkably conductive, thermally stable, and even antimicrobial materials. Yet, their potential has been hindered by poor mechanical properties. Herein, a double network (DN) ionogel crafted from 1-Ethyl-3-methylimidazolium chloride ([Emim]Cl), acrylamide (AM), and polyvinyl alcohol (PVA) was constructed. Tensile strength, fracture elongation, and conductivity can be adjusted across a wide range, enabling researchers to fabricate the material to meet specific needs. With adjustable mechanical properties, such as tensile strength (0.06-5.30 MPa) and fracture elongation (363-1373%), this ionogel possesses both robustness and flexibility. This ionogel exhibits a bi-modal response to temperature and strain, making it an ideal candidate for strain sensor applications. It also functions as a flexible strain sensor that can detect physiological signals in real time, opening doors to personalized health monitoring and disease management. Moreover, these gels' ability to decode the intricate movements of sign language paves the way for improved communication accessibility for the deaf and hard-of-hearing community. This DN ionogel lays the foundation for a future in which e-skins and wearable sensors will seamlessly integrate into our lives, revolutionizing healthcare, human-machine interaction, and beyond.


Assuntos
Língua de Sinais , Humanos , Álcool de Polivinil/química , Monitorização Fisiológica , Dispositivos Eletrônicos Vestíveis , Géis/química , Imidazóis/química , Técnicas Biossensoriais , Acrilamida , Resistência à Tração
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